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Soxhlet

Soxhlet is considered an exhaustive extraction and usually performed overnight. It is a continuous process which by its nature produces higher concentrations than other less exhaustive techniques and sometimes extracts unwanted substances. The process involves the soil sample being in contact with the solvent and with each cycle the extract liquid drains completely from the soil sample. [Pg.142]

This process is repeated for up to 16 hours or until the extract liquid is clear. Water affects the polarity of the solvent and can also prevent contact between the extraction liquid and the matrix. It is therefore recommended that the soil be chemically dried or oven dried (up to 35°C with risk of loss of volatiles) prior to extraction. Crushing will also aid the extraction process. [Pg.143]


Soxhlet Extraction. Occasionally a crude product (often of natural occurrence) is obtained, from which a particular component may be isolated by repeated extraction with a hot soK-ent. For this purpose, Soxhlet s Extraction Apparatus (Fig. 19) is usually employed. [Pg.37]

For extraction purposes, a Soxhlet apparatus (Fig. 23(H)) can be inserted between a flask of boiling solvent and the reflux condenser A above. This apparatus is similar in design to that shown in Fig. 19, p. 3b in the type shown in Fig. 23(H) the hot extract continuously overflows through the side- tube into the boiling solvent below, but the syphon type shown in Fig. 19 is also available. [Pg.47]

Solids by solvents. The various forms of Soxhlet apparatus illus trated in Section 11,44 can be purchased with ground glass joints. A simplified form, in which the fragile side tubes are absent, is shown in Fig. II, 58, 1. The material to be extracted, if of granular form, may rest upon a sintered glass disc or upon a removable septum ... [Pg.222]

If the outlet of the siphon tube at the bottom of the Soxhlet apparatus is well plugged with cotton wool so that no finely-divided bariuna hydroxide can pass into the flask, the barium hydroxide may be placed directly into the extractor until the latter is three-quarters full the remaining space is filled with glass wool. [Pg.352]

The experimental conditions for conducting the above reaction in the presence of dimethylformamide as a solvent are as follows. In a 250 ml. three-necked flask, equipped with a reflux condenser and a tantalum wire Hershberg-type stirrer, place 20 g. of o-chloronitrobenzene and 100 ml. of diinethylform-amide (dried over anhydrous calcium sulphate). Heat the solution to reflux and add 20 g. of activated copper bronze in one portion. Heat under reflux for 4 hours, add another 20 g. portion of copper powder, and continue refluxing for a second 4-hour period. Allow to cool, pour the reaction mixture into 2 litres of water, and filter with suction. Extract the solids with three 200 ml. portions of boiling ethanol alternatively, use 300 ml. of ethanol in a Soxhlet apparatus. Isolate the 2 2- dinitrodiphenyl from the alcoholic extracts as described above the 3ueld of product, m.p. 124-125°, is 11 - 5 g. [Pg.528]

The high sodium ion concentration results in facile crystallisation of the sodium salt. This process of salting out with common salt may be used for recrystallisation, but sodium benzenesulphonate (and salts of other acids of comparable molecular weight) is so very soluble in water that the solution must be almost saturated with sodium chloride and consequently the product is likely to be contaminated with it. In such a case a pure product may be obtained by crystallisation from, or Soxhlet extraction with, absolute alcohol the sul-phonate is slightly soluble but the inorganic salts are almost insoluble. Very small amounts of sulphones are formed as by-products, but since these are insoluble in water, they separate when the reaction mixture is poured into water ... [Pg.548]

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. [Pg.571]

A solution of 2,3-dimethylindole (145 g, 1 mol) in dry dioxan containing hydroquinone (100 mg) was treated with JV,JV,JV-trimethylbenzylammonium ethoxide (5 ml of a 40% solution in MeOH) and warmed to 35 C. Freshly distilled acrylonitrile (150 ml, 2.5 mol) was added at a rate such that the temperature did not rise above 40°C. The solution was then stirred overnight and diluted with 10% aq. acetic acid (11). The solution was extracted with CH Clj and the extract was washed with water and dried (MgS04). extract was then mixed with silica gel (800 g) and the solvent removed in vacuo. The silica was placed in a Soxhlet extractor and extracted with cyclohexane. The extract deposited the product as colourless needles (125 g, 63% yield). [Pg.91]

Soxhlet lactometer has a scale from 25° to 35° corresponding to specific gravities from 1.025 to 1.035 respectively. [Pg.141]

In a solid-phase extraction the analytes are first extracted from their solution matrix into a solid adsorbent. After washing to remove impurities, the analytes are removed from the adsorbent with a suitable solvent. Alternatively, the extraction can be carried out using a Soxhlet extractor. [Pg.224]

Several standard methods for the quantitative analysis of food samples are based on measuring the sample s mass following a selective solvent extraction. For example, the crude fat content in chocolate can be determined by extracting with ether for 16 h in a Soxhlet extractor. After the extraction is complete, the ether is allowed to evaporate, and the residue is weighed after drying at 100 °C. This analysis has also been accomplished indirectly by weighing a sample before and after extracting with supercritical GO2. [Pg.264]

Ash is a measure of residual sodium acetate. A simple method consists of dissolving the PVA in water, diluting to a known concentration of about 0.5 wt %, and measuring the electrical conductivity of the solution at 30°C. The amount of sodium acetate is estabUshed by comparing the result to a cahbration curve. A more lengthy method involves the extraction of the PVA with methanol using a Soxhlet extractor. The methanol is evaporated and water is added. The solution is titrated using hydrochloric acid in order to determine the amount of sodium acetate. [Pg.487]

Analytical Supercritical Fluid Extraction and Chromatography Supercritical fluids, especially CO9, are used widely to extrac t a wide variety of solid and hquid matrices to obtain samples for analysis. Benefits compared with conventional Soxhlet extraction include minimization of solvent waste, faster extraction, tunabihty of solvent strength, and simple solvent removal with minimal solvent contamination in the sample. Compared with high-performance liquid chromatography, the number of theoretical stages is higher in... [Pg.2004]

This modified Soxhlet extractor was devised by D. F. McFarland. [Pg.100]

Soxhlet thimbles and filter papers may contain traces of lipid-like materials. For manipulations with highly pure materials, as in trace-pesticide analysis, thimbles and filter papers should be thoroughly extracted with hexane before use. [Pg.3]

Trace impurities in silica gel for TLC can be removed by heating at 300° for 16h or by Soxhlet extraction for 3h with distilled chloroform, followed by 4h extraction with distilled hexane. [Pg.3]

For extraction of solid materials with a solvent, a Soxhlet extractor is commonly used. This technique is applied, for example, in the alcohol extraction of dyes to free them from insoluble contaminants such as sodium chloride or sodium sulfate. [Pg.7]

Water-soluble salts are best purified by preparing a concentrated aqueous solution to which, after decolorising with charcoal and filtering, ethanol or acetone is added so that the salts crystallise. They are collected, washed with aqueous ethanol or aqueous acetone, and dried. In some cases, water-soluble salts can be recrystallised satisfactorily from alcohols. Water-insoluble salts are purified by Soxhlet extraction, first with organic solvents and then with water, to remove soluble contaminants. The purified salt is recovered from the thimble. [Pg.68]

Amberlite IRA-904 Anion exchange resin (Rohm and Haas) [9050-98-0]. Washed with IM HCl, CH3OH (1 10) and then rinsed with distilled water until the washings were neutral to litmus paper. Finally extracted successively for 24h in a Soxhlet apparatus with MeOH, benzene and cyclohexane [Shue and Yan Anal Chem 53 2081 1981]. Strongly basic resin also used for base catalysis [Fieser Fieser Reagents for Org Synth 1511, Wiley 1967]. [Pg.102]


See other pages where Soxhlet is mentioned: [Pg.368]    [Pg.397]    [Pg.398]    [Pg.123]    [Pg.154]    [Pg.223]    [Pg.352]    [Pg.352]    [Pg.550]    [Pg.550]    [Pg.551]    [Pg.626]    [Pg.774]    [Pg.878]    [Pg.880]    [Pg.954]    [Pg.418]    [Pg.917]    [Pg.60]    [Pg.10]    [Pg.226]    [Pg.346]    [Pg.242]    [Pg.242]    [Pg.235]    [Pg.61]    [Pg.135]    [Pg.14]   
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Accelerated Soxhlet Extraction

Automated Soxhlet

Automated Soxhlet extraction

Carbon soxhlet extractors

Cleaning by Soxhlet extraction

Continuous extractors Soxhlet extractor

Corrosion Soxhlet tests

Dichloromethane Soxhlet

Dichloromethane Soxhlet extraction

Extraction, Soxhlet

Extraction, Soxhlet with ether

Fast Soxhlet

Fatty acid Soxhlet extraction methods

Focused microwave-assisted Soxhlet

Focused microwave-assisted Soxhlet extraction

Focused microwave-assisted Soxhlet extraction (FMASE

Focused microwave-assisted Soxhlet extractor

Leaching with soxhlet apparatus

Lipids Soxhlet extraction

Microwave-assisted extraction Soxhlet

Plants Soxhlet extraction

Plasticisers Soxhlet

Poly soxhlet extraction analysis

Polyurethane foam soxhlet extraction

Solids Soxhlet

Solvent extraction Soxhlet

Soxhlet apparatus

Soxhlet apparatus, lipid extraction with

Soxhlet assembly

Soxhlet chromatography

Soxhlet extraction apparatus

Soxhlet extraction characteristics

Soxhlet extraction direct

Soxhlet extraction method

Soxhlet extraction polymer purification

Soxhlet extraction resin cleanup

Soxhlet extraction separation techniques

Soxhlet extraction sludges

Soxhlet extraction techniques

Soxhlet extraction thimbles

Soxhlet extraction, modification

Soxhlet extractions comparison

Soxhlet extractions determinations

Soxhlet extractions polychlorinated biphenyl

Soxhlet extractions pressurized fluid extraction

Soxhlet extractions supercritical fluid extraction

Soxhlet extractor

Soxhlet extractor technique

Soxhlet lactometer

Soxhlet reactions

Soxhlet solution

Strength Soxhlet

Total size by Soxhlet method

Ultrasonic extraction comparison with Soxhlet

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